Data compression methods exist in such fields as medicine for compressing data measured by an ultrasonic diagnostic apparatus in order to produce images. An ultrasonic diagnostic apparatus emits ultrasonic waves towards a subject (for example a body of a human or animal), and measure the internal state (such as the flow of internal fluids (such as blood)) of the subject by detecting reflected waves.
Imaging methods include, for example, a B-mode for imaging brightness, an M-mode for imaging movement, color Doppler imaging (CDI) for imaging velocity of blood flow (speed and direction), dispersion, and power data (intensity of reflected ultrasonic wave), and power Doppler imaging (PDI) for imaging the reflection intensity of a Doppler shifted signal.
CDI renders an image by superimposing Doppler data including blood flow data (speed and distribution) and power data on B-mode data.
In related data compression methods logarithmic compression is only applied to the B-mode data, and the color Doppler data is not compressed. However, there is a need for greater data compression due to the increase in the volume of data accompanying such developments as increasingly high precision of ultrasonic diagnostic apparatuses.